Final answer:
Pulleys make it easier to lift objects because they allow the effort force to be applied over a longer distance, thus reducing the force needed and spreading out the work. Using a pulley can also increase power if the work is done in less time, as seen in a comparison between carrying an object up stairs versus using a pulley system.
Step-by-step explanation:
Pulleys make things easier because they spread out work. In physics, the concept of work is defined as the product of force (f) multiplied by the distance (d) over which the force is applied. When using a pulley system, a person can apply a smaller effort force over a longer distance to achieve the same amount of work compared to lifting the object directly. This is because the pulley system allows the work to be distributed over a greater distance.
Consider an example where a woman is lifting a TV to the second floor of a building using a pulley, while a man carries the same TV up the stairs. Both methods might take different times to achieve the task, with the pulley possibly allowing the TV to be lifted faster. Since work is the same for both (moving the same mass over the same vertical distance), it's the power that differs, which is the rate of doing work (work done over the time taken). The pulley system enables the woman to exert less force over a longer time, which can make the task feel easier and could increase the power if the work is done in a shorter amount of time.